It sounds very much like GERD or asthma. You could try some OTC acid reflux meds to start with. I would suggest something with ranitidine or omeprazole. You can take both of them. omeprazole should be taken early in the day to mid afternoon and the ranitidine works best at night.
If these don't work, ask your doctor for spirometry or methocholine chalenge. If they do work, you should ask your dr for an endoscope to check for lessions in the esopagus because of the long time you have had the symptoms.
Feel better.
It is nice of you to take time out and give suggestion.I will attempt to follow your recommendations and report the results
regards
dathu